2.25 Anatomical Observations Concerning the Eggs of Viviparous Animals

Abstract

To confirm and light up observations of friends on the reproduction of animals from an egg, let me add to their works what divine generosity pointed out to me from the dissections of various animals concerning the eggs of the viviparous. By egg I mean not only the round vesicles full of humour which constitute a great part of the testicles but also the chorion with all its contents. I use terms which are usual for most people, the testicles of females meaning the ovaries, the uterine tubes and horns, and the uterus meaning the oviducts.

OPH 25, vol. II, 159–166: Observationes anatomicae spectantes ova viviparorum. In the former treatise Historia dissecti piscis ex canum genere, OPH XXIV, Steno, in describing the dissection of a shark, for the first time maintained, that the testes of women were analogous to the ovaria of oviparous animals and ought to be called by that name. Steno also said that he hoped to take up this subject again, when he had made some more investigations. These notes, for the most part based upon dissections in the following years, from and including the year 1667, although a few of them date as far back as to the stay in Holland, are what Steno published in this Treatise; he probably felt that he would not succeed in completing the intended and more extensive work on this subject. The manuscript may have been handed over to Thomas Bartholin, while Steno was living in Copenhagen as Anatomicus Regius, but the treatise was published in Acta Hafniensia. vol. II. Hafniae 1675 (as No. LXXXVIII, pp. 210–218) not until Steno had left Denmark, and not till three years after the publication of Regneri De Graaf de mulierum organis generationi inservientibus tractatus novus, Lvgdvni Batav. 1672, and of Johannis Swammerdami… Miracvlvm natvrae sive uteri muliebris fabrica…, Lugduni Batavorum 1672. The first small section of the treatise was, no doubt, added as a kind of introduction to the observations, which are only connected by their subject being the same. In that section Steno also refers to the observations of de Graaf and Swammerdam, in the words amicorum observationes. See, furthermore, Gosch, Udsigt over Danmarks zoologiske literatur, II 1. Kjøbenhavn 1872, pp. 235–237.